At least one example embodiment relates to a memory system, and more particularly, to a non-volatile memory system and a method of managing the power of the same.
Demand for non-volatile memory systems supporting a large capacity has been increasing. A non-volatile memory system is a data storage system using a non-volatile semiconductor memory. A flash memory apparatus is a non-volatile memory system usually used in portable electronic equipment. A flash memory is non-volatile like a hard disk and has a fast access speed and low power consumption and is thus widely used in embedded systems or mobile systems.
Flash translation layer (FTL) is software for managing flash memory. The FTL receives a logical address from a file system and translates the logical address into a physical address. The logical address is an address that is recognized in the file system and the physical address is an address that is recognized in the flash memory. The FTL refers to an address mapping table to manage address mapping. The address mapping table stores a logical address and a physical address corresponding to the logical address. The size of the address mapping table may vary with a mapping unit. A page mapping method, a block mapping method, and a hybrid mapping method are common mapping methods.
In the page mapping method, mapping is performed in units of pages. In the block mapping method, mapping is performed in units of blocks. In the hybrid mapping method, both the page mapping method and the block mapping method are used.
Usually, a single block includes several tens or hundreds of pages. Accordingly, the size of the mapping table in the page mapping method is several tens or hundreds of times larger than that in the block mapping method. In other words, an address mapping table in the page mapping method uses more memory than an address mapping table in the block mapping method.
An address mapping table is usually driven in volatile random access memory (RAM). When the address mapping table is loaded into and used in static RAM (SRAM), the block mapping method is usually used since the size of the SRAM is small. When the address mapping table is loaded into and used in large-capacity dynamic RAM (DRAM), the page mapping method is usually used.
Using DRAM causes standby current and operating current to increase, resulting in an increase of power consumption of a non-volatile data storage device and an electronic system (e.g., a portable electronic system) including the non-volatile data storage device.